Steam-boiler



(No Model.)

l T. L. STURTEVANT.

STEAM BOILER.

No. 498,998. 13899111.98 Aug. 18, 1889.

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UNITED STATES PATENT OFFICE.

THOMAS IJ. STURTEVANT, OF FRAMINGHAM, MASSACHUSETTS.

sTEuvl-BOILER.`

SPECIFICATION formingpart of Letters Patent No. 408,996, dated August 13, 1889.

Application filed April 22, 1889. Serial No. 308,098. (No model.)

To all whom it may concern.'

VANT, a citizen of the United States, residing at Framingham, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Steam-Boilers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of referencemarked thereon, which form a part of this speciiication.

This invention relates to steam-boilers, particularly that class having a forced circulation, wherein water introduced continuously at one end of the tubular system escapes in the form of steam at the other and opposite end of said system.

The object of this invention is to provide a large heating-sulface; further, in connection therewith, to obviate the objection which would be caused by the use of the additional tubular iiues necessary to produce such heating-surface, Ipropose to Hatten the same. By this arrangement and construction the interior space of the external shell or element is less obstructed, ample room is furnished for the escape of smoke and gases, while at ,the same time an equal area or surface for heating the liquid still exists.

The drawings represent, in Figure l, a vertical longitudinal sectional elevation of a boiler containing my improvements. Fig. 2 is a transverse section on line oc fc, looking toward the lamp end of the boiler. Fig. 3 is an end View of one of the unions.

In the drawings, the boiler, of a horizontal type, asa complete organization is shown at A, consisting of a main exterior shell or element B, which is a double-tube section composed of the tubes a a ,having their opposite adjacent ends closed by solid annular rings b b, secured by transverse bolts or pins. In this way a tight jointis produced and a steamgenerating chamber c, formed capillary in the present instance. One end of this elementB is connected with a smoke-stack C, while at the opposite end is located, preferably, a hydrocarbon-burner D, of any suitable descriplatter, as shown in the drawings.

tion. The water-supply pipe is at E, and united with the element B at the end opposite the lamp, to permit the water to become gradually heated as it is forced toward the lamp or heating agency.

. Centrally of the bore of the shell B are grouped a number of small tubes d d, circular their entire length and terminating at the lamp end of the boiler in the union F, which connects with the steam-discharge e, and at the chimney end of said boiler in the union G. Thus the central portion of the boiler is occupied while a space exists between the external shell or element B and the group of pipes or tubes d d. To provide for a still greater heating-surface, and thereby make available all the interior space of the element B, I dispose about the central pipes d (l a series of tubes f f, which are iiattened or made oval for their entire length, with the exception of their extremities, which are circular to adapt them to engage with elbows connecting them with other parts of the system. By this means each pipe 'presents the same heatingsurface which it otherwise would were it circular in cross-section at all points, and the interior space of the boiler is not so crowded, while the smoke and gases of combustion are free to escape under a natural draft. Said group of pipes terminates at the chimney end of the boiler within the union G, entering the The opposite ends are united with pipes 7L h, attened in that portion of their length adjacent to said group f f. These pipes h communicate by suitable iittings with the exterior shell or element. B. Heat being applied at the lamp end and water being continually introduced by liquid-forcing apparatus through the pipe E, the circulation is as follows: Through the generating-chamber c, in the double-tube section B, toward the lamp end of the boiler; thence, by way of tubes h, in the reverse direction, or toward the chimney end thereof, again toward the lamp end, and return by way of the group of flattened or oval tubes f f to the union G. From here the water, which is now in the form of steam, is transmitted through the circular iiues d d, wherein itis superheated and dried, to the union F, whence it is conveyed by the discharge-pipe e to the source IOC) tobe supplied. '.Ihe employment of these flattened tubes within the combustion-chamber or smoke-passages of aboiler subserves several important ad vantages-a freer passage for the products of combustion is secured and at the same time the surface of the metal tubes exposed to the lire or the water is not din1in ished. Further, the flattened tubes in a tubular boiler diminish the amount ot' water in the tubes without reducing the amount ol tube-surface exposed to the water or fire. The narrower tubes will heat more (plickly, and the water heating more rapidly will circulate more rapidly.

l do not desire to claim, broadly, flattened tubes for steam-generating purposes, since I am aware that f'laf tened tubes have been used `in boilers.

\Vhat I desire to claim is l. A boiler for steam-generating purposes composed of an exterior shell, a series of; eylindrieal tubes Centrally of ifs bore, a group of flattened tubes circular in Cross-section at their extremities, and between said shell and the inner tubes the smoke-flue at one end and the heating agency at the opposite end of said boiler, with means for supplying water and discharging steam, substantially as and for purposes herein set forth.

2. In a steam-boiler, the double-tube elcment B, the central group of tubes if (l, the unions l? G, in which said tubes terminate, combined withv the flattened tubes ff, eireular at their extremities, and the tubes 7l 71 by which the union (l is united withthe element l5, the water-supply pipe E, steam-discharge e, and a suitable heating agent, substantially as specified.

In testimony whereof I affix lnysignafiure in presence of two witnesses.

THOMAS L. STUR'IEVAN'I.

\\'itnesses:

(MnoLiNE F. lViLsoN, W. Il. BLACKNALL. 

